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Showing: 41 - 50 of 421 results
  1. CrispyCrunch: High-throughput Design and Analysis of CRISPR+HDR Experiments

    Type
    Blog Post
    Published
    Feb. 7, 2019, 2:16 p.m.
    ...CrispyCrunch is how it mutates guide sequences to prevent re-cutting of the sequence inserted by HDR. Although this...algorithm then compares the guide sequence to every possible 23bp sequence (protospacer + PAM) in the target... often because the HDR inserted sequence splits up the guide sequence.) If neither of the above are options...codons in the guide sequence, one by one, from the PAM outwards so that the DNA sequence is altered but the...needed to design guide RNAs, donor templates and sequencing primers for quality control. At such a scale,...requires the additional step of mutating guide sequences in a way that prevents re-cutting but does not...not be enough to prevent re-binding. Lastly, the sequence inserted by HDR may inadvertently re-create a ...
  2. Optimizing Donor DNA for Enhanced CRISPR Genome Editing

    Type
    Blog Post
    Published
    March 24, 2016, 2:30 p.m.
    ...end-joining (NHEJ) pathway disrupt target gene sequences (thus inactivating genes), while breaks repaired... directed repair (HDR) pathways can modify the sequence of a gene (thus altering its function). HDR is...rational approach to improve the efficiency of sequence replacement by HDR. Understanding Cas9 biophysics...from in vitro studies) to boost the efficiency of sequence replacement in vivo. We discovered that single...from Richardson et al., 2016.   dCas9 enables sequence replacement without cutting Our in vitro results... thus wondered if such a structure could drive sequence replacement in cells. Targeting three dCas9 molecules...molecules to a precisely spaced region allowed sequence replacement rates of approximately 1%. This is...
  3. Progress Towards a PAM-Free CRISPR

    Type
    Blog Post
    Published
    March 7, 2024, 2:39 p.m.
    ...sneaky little bit of sequence that you hope is present next to the "perfect" guide sequence for your genome... a Protospacer Adjacent Motif (PAM) sequence. If the gRNA sequence is suitable, but there is no PAM next...typically selected by the ‘quality’ of the gRNA sequence, including propensity for off-targets, secondary...To add insult to injury, the most utilized PAM sequence, that of SpCas9, is NGG. Assuming all nucleotides...Cas enzyme or evolve one that uses a PAM with no sequence constraints, or at least has looser or different...such as Cpf1/Cas12a, which recognizes the PAM sequences of TTTV. While all of these enzymes certainly ...equal; just because an enzyme recognizes a PAM sequence in your site doesn’t mean it’s suitable for your...
  4. How to Deposit Your Plasmids with Addgene

    Type
    Blog Post
    Published
    Feb. 27, 2024, 2:15 p.m.
    ...   Step 1: Sequences, Maps, and Files Please provide any full or partial plasmid sequences and any vector...The more sequence data available, the better. We highly encourage you to upload full sequence data whenever...files, etc). We can accept sequence files in any format. Figure 6: Add sequence, maps, and files. Step 2...addgene.org along with your GenBank files, plasmid sequences, and/or maps. Add plasmids to your article After...plasmid with one or more genes, protein coding sequences, or other elements inserted into it. You will ...shRNA A plasmid with one or more gRNA or shRNA sequences cloned into it. gRNAs are used for directing CRISPR...expression of mRNAs with complementarity to the shRNA sequence. Empty backbone A plasmid designed for cloning...
  5. Anatomy of a Plasmid Page at Addgene

    Type
    Blog Post
    Published
    Feb. 4, 2016, 3:30 p.m.
    ... from Addgene’s sequencing reactions (‘Addgene Sequences’).  These sequences are provided in FASTA format... your research! Sequence information: Depositors may provide full or partial sequence information for ...be made available as ‘Depositor Sequences’. Additional partial sequence information is also available from...auto-generate a plasmid map based off of the plasmid sequence and feature information given by our depositors...example) and can be analyzed using Addgene’s Analyze Sequence tool. Excellent, how can I check if the plasmid... own lab.  If depositors have provided primer sequences for use, these are listed.  We also provide a ...a link to our list of common primers used for sequencing. Growth in Bacteria: This section describes how...
  6. Plasmids 101: Methylation and Restriction Enzymes

    Type
    Blog Post
    Published
    June 30, 2016, 2:30 p.m.
    ...specific DNA sequences and companion endonucleases that recognizes and cleave the same DNA sequence if not ...methyltransferases, methylate DNA at particular sequences to prevent them from being degraded by restriction...with any restriction modification systems, their sequences may overlap with restriction sites, inhibiting...therefore have methylated adenines in any GATC sequences found in the plasmid. When the PCR products are...plasmids which can later be verified by Sanger sequencing. How can I tell if my enzyme will cut? Whether...enzyme is affected by methylation, knowing the sequence of the DNA surrounding your restriction site(s...methylation), the figure below illustrates how sequence visualization software (we used Snapgene here)...
  7. A Needle in a Base-Stack: Cas9 Structural Biology

    Type
    Blog Post
    Published
    June 4, 2024, 1:15 p.m.
    ...the DNA and test for sequence complementarity with its guide RNA. If the sequence is recognized, Cas9 ...bases, or why it’s so important to choose a target sequence with a nearby protospacer-adjacent motif (PAM)...recognize PAMs, so it associates with random DNA sequences (Sternberg et al., 2014). The nuclease lobes are...editing requires three major steps: RNA loading, DNA sequence recognition, and DNA cleavage. RNA loading Once... (left) and transparent (right). The RNA guide sequence is extended as a single unpaired strand in the...anti-repeat duplex of the guide RNA, confirming its sequence. This region of the protein varies between Cas9... RNA loading: the structure to interrogate the sequence isn’t in place yet.     Figure 4: S. pyogenes...
  8. 3 Tips to Improve HDR Efficiency for CRISPR Editing in Human Cells

    Type
    Blog Post
    Published
    Sept. 5, 2017, 1:58 p.m.
    ...introduction of specific sequence changes. To generate a specific sequence change the cell must undergo...CRISPR/Cas9 extensively for the purpose of making sequence-specific changes in human induced pluripotent ...oligodeoxynucleotide (ssODN), which contains the intended sequence changes to be incorporated into the edited genome...our excitement turned into frustration when we sequenced our cells and found how inefficiently our edits... – but avoid NAG) or guide RNA target (“seed”) sequence. The idea was that these “blocking mutations” ...mutations prevent CRISPR from re-cutting the target sequence once the desired edit has been introduced. We ...So if the locus does not allow blocking the PAM sequence (e.g. if it would lead to a missense or nonsense...
  9. Plasmids 101: Sequence and Ligation Independent Cloning (SLIC)

    Type
    Blog Post
    Published
    Sept. 26, 2024, 1:15 p.m.
    ...issue is sequence similarity. If fragments in a multicomponent assembly have 5′ or 3′ sequence homology...If cloning methods had personalities, SLIC (sequence- and ligation-independent cloning) would be a true...reliable cloning method, but it is limited by its sequence constraints. The long overhangs must not contain... often limited to specially designed plasmids. Sequence- and ligation-independent cloning: A SLIC makeover...depositor Stephen Elledge. His new method, named sequence- and ligation-independent cloning (SLIC), eliminated...and linearized vectors must have homologous DNA sequences (20–60 bp) on either end and single-stranded 5...multicomponent assembly, as fragments with overlapping sequence homology can be assembled in a unique order with...
  10. Plasmids 101: Cre-lox

    Type
    Blog Post
    Published
    Jan. 13, 2015, 3:47 p.m.
    ... long asymmetric core spacer sequence. The asymmetry in the core sequence gives the loxP site directionality...the canonical loxP sequence is ATAACTTCGTATA-GCATACAT-TATACGAAGTTAT. The loxP sequence does not occur naturally...in P1) sites are 34-base-pair long recognition sequences consisting of two 13-bp long palindromic repeats...inserting loxP sites at deliberate locations in a DNA sequence allows for very specific manipulations as discussed...or on separate pieces of DNA. Both 13bp repeat sequences on a single loxP site are recognized and bound...: If the sites face in the same direction, the sequence between the loxP sites is excised as a circular...indicates which bases may vary from the canonical sequence. Among these are loxN (GtATACcT), lox2272 (GgATACtT...
Showing: 41 - 50 of 421 results